The former Olympic gold medalist made his revelation during a two-hour interview with US journalist Diane Sawyer and while Bruce admitted that Khloe Kardashian was finding the news tough to take in, she was one of the first family members to post a message of support for Jenner.
After retweeting Ellen Degeneres' message of support, Khloe posted:
Just finished watching the #BruceJennerInterview with the family. Bruzer, I'm soooo proud of you! Dads really are heros ❤️— Khloé (@khloekardashian) April 25, 2015
Her siblings also shared kinds words online:
Couldn't be a more proud daughter. With courage and bravery, let's change the world. I am honored to stand by Bruce's side and support him.— Kourtney Kardashian (@kourtneykardash) April 25, 2015
You have always been a role model to me and now more than ever, I look up to you. LOVE YOU‼️‼️👐👐— ROBERT KARDASHIAN (@robkardashian) April 25, 2015
so very proud of you, my hero.— Kendall Jenner (@KendallJenner) April 25, 2015
Understandingly, this has been very hard for me. You will hear what I have to say when I'm ready to but...— Kylie Jenner (@KylieJenner) April 25, 2015
..this isn't about me. I'm so proud of you, Dad. You are so brave. My beautiful Hero.— Kylie Jenner (@KylieJenner) April 25, 2015
Kris Jenner also posted a loving message:
Not only was I able to call him my husband for 25 years and father of my children, I am now able to call him my hero.— Kris Jenner (@KrisJenner) April 25, 2015
"She caught me one time [wearing women's clothes], walked in, she said nothing, she jumped in the car and went for a ride. We never talked about it again," Bruce explained. "Then she said another time, 'what's going on?'
"I said okay, I told her all my issues, this and that, after that was over with I felt much better but when I brought it up again, she said she thought it was one of these subject she couldn't talk about."
However later, after receiving some wonderful advice from her husband Kanye West, Kim returned to Bruce with some wise words of her own, telling him: "You gotta rock it, girl!"
Jenner's children from his previous marriage to Linda Thompson appeared in his documentary, and Brandon shared his thoughts of Jenner's transition.
"There is a thread throughout his life that there was a life he wanted to live," he told Diane Sawyer. "There were clues, I feel like I'm getting an ungraded version of my dad.
“I'm not handling this perfectly. When I see my dad as a woman, it might be a bit shocking at first. We can ask any questions we want.”
After the show, Brandon shared a super-cute throwback snap.
During the two-hour interview, Jenner stated, "I am a woman," revealing that he has dressed in women's clothes since he was a child.
"What I'm doing is going to do some good and we are going to change the world, we are going to make a difference," he said. "If the Kardashian show ['Keeping Up With The Kardashians'] gave me that foot to go and do something then I'm happy with that.”